Advances in fabrication of increasingly miniscule integrated circuit (IC) devices have coincided with advances in the use of semiconductors to form mechanical and electromechanical structures. Generally referred to as microelectromechanical systems (MEMS), these minute devices are formed via fabrication procedures typically associated with integrated circuits and procedures unique to MEMS alone. MEMS development has given rise to miniature devices at sizes far below what was previously attainable and to entirely new devices altogether. MEMS devices are used in power generation, light projection, force sensing, switching, and locomotion to name merely a few examples, and have found applications in both the home and the laboratory.
One promising application of MEMS devices includes the use of nano-scale and micro-scale electrodes formed on an IC substrate to measure and stimulate living tissue. The MEMS electrodes may be used to provide electrical stimulation and to measure electrical activity. These electrical potentials may represent sensory perception, muscular control, and other neural signals, and the electrodes may provide an avenue to restore lost neural function by stimulating targeted neurons. However, the promised benefits have not yet been fully achieved. Key complications include providing localized measurement and electrically isolating the regions of interest. For these reasons and others, existing MEMS devices have been generally adequate but have not been entirely satisfactory in all respects.